Self-mutilation occurs when dogs lick or bite themselves excessively, causing mild to severe injury to their skin and sometimes the underlying tissues, too. Causes of self-mutilation may be medical or psychological. Self-mutilation resulting from medical causes will resolve once the medical condition has been successfully treated. Self-mutilation resulting from psychogenic causes is often chronic, and is refractory to anything other than stress/conflict alleviating strategies and/or anti-obsessional medication.
Tail chasing/biting, acral lick dermatitis, and flank sucking are three psychogenic causes of self-mutilation. Tail biting is an extreme end point of compulsive tail chasing. If a tail-chasing dog catches his tail, it may inflict serious injury upon itself, including partial or complete amputation of the tail. Affected dogs have hemorrhaged to death as a result of auto-amputation of their tail.
Acral lick dermatitis is a repetitive licking disorder that may lead to ulceration and infection of the skin of the extremities of the limbs.
Flank sucking is a nursing compulsion in which the dog sucks at its own flank until it is denuded of hair. Ulceration of the skin overlying the flank sometimes results.
These behaviors are now viewed as obsessive-compulsive disorders. An obsession is a constantly recurring thought ("I should lick my foot"); a compulsion is a repetitive action (licking the foot). Compulsions may follow obsessions or may occur without them. Obsessions are hard to verify in animals. Medical conditions may initiate or derive from compulsive self-mutilation. Some medical conditions that may be associated with self-mutilation include:
Allergies: Fleas, foods or inhalants (may initiate acral lick dermatitis)
Infection: Bacterial, fungal or parasites (may initiate or be a sequel of any of the conditions listed above)
Pain: Previous trauma or joint disease (may precipitate compulsive over-grooming)
Where psychogenic factors are involved, self-mutilation will continue long after direct medical causes of the behavior have resolved. It is as if the medical problem starts a behavioral pendulum swinging. Compulsive behaviors may be reinforced if they attract the owner's attention. Anxiety or stress caused by long periods of confinement, social isolation, harassment from another pet, repeated exposure to frightening stimuli, such as loud noises will promote and exacerbate obsessive-compulsive disorders, including self-mutilation.
Some dogs appear to be prone to psychogenic self-mutilation. Dobermans, Great Danes, Labrador retrievers, Irish setters and German shepherds are susceptible to acral lick dermatitis. Flank sucking is almost exclusively a Doberman condition. Tail chasing affects primarily bull terriers and German shepherds.
What to Watch For
Look for excessive licking, hair loss, rashes, sores, and/or brown staining of the haircoat. You should try to note what triggers the behavior, e.g. the proximity of another pet, external stimuli, the absence of a favored family member, etc.
Rule out all medical contributions to the problem by having your veterinarian run the requisite tests such as:
Biopsy of skin samples
Bacterial culture and sensitivity
Hypoallergenic (elimination) diet
Complete blood count
Serum chemistry profile
After the medical causes of self-mutilation have been ruled out or treated, the compulsion must be addressed. The following therapies are recommended:
Take any and all measures appropriate to reduce stress in the dog's life including environmental enrichment and avoidance of precipitating events. Increase your dog's social interactions and exercise. Employ longer or more frequent play sessions and minimize the time your dog spends alone.
Physical restraints, such as bandages or Elizabethan collars may be necessary in the short term but are frustrating for the pet and are better avoided, if possible.
Anti-obessional medication. Selective (or preferential) serotonin reuptake inhibitors: e.g. fluoxetine (Prozac®), clomipramine (Clomicalm®), sertraline (Zoloft®). Note: Older tricyclic anti-depressants, like amitriptyline (Elavil®), are much less effective.